Atypical morphologic presentation of biliary atresia and value of serial liver biopsies

Background: Liver biopsy findings are important in diagnosing extrahepatic biliary atresia. Diffuse ductular proliferation is a characteristic finding. We describe four patients with conjugated hyperbilirubinemia in whom the initial liver biopsy findings showed a lack of ductular proliferation. despite subsequent development of biliary atresia. Results: On initial biopsy. paucity of intrahepatic bile ducts was present in three of four patients. with a bile duct to portal space ratio of 0.3 to 0.4 (normal, 0.9-1.8). A normal bile duct to portal space ratio of 1.0 was observed in the fourth patient. Ductular proliferation became apparent in three Subjects between 9 and 12 weeks of age. and biliary atresia was noted at the time of a Kasai portoenterostomy. The fourth child had well-developed biliary cirrhosis at liver transplantation. Conclusions: Changes characteristic of biliary atresia may appear even after 9 weeks of age. Bile duct paucity and normal bile duct to portal space ratio do not preclude the subsequent development of biliary atresia. Infants with unexplained conjugated hyperbilirubinemia and acholic stools should undergo sequential liver biopsies until clinical improvement occurs or until biliary atresia call be excluded from the differential diagnosis.